Switch-based Independent Antagonist Actuation with a Single Motor for a Soft Exosuit

TL;DR

This paper introduces a switch-based mechanism for a single motor to control antagonist cables in a soft exosuit, enabling multi-DoF actuation with reduced actuator count, though with some latency in switching.

Contribution

A novel switch-based control mechanism allowing a single motor to actuate multiple cable paths in a soft exosuit, simplifying design for multi-joint applications.

Findings

Switching latency of 298.24ms demonstrated.

Mechanism enables multi-DoF actuation with one motor.

Potential for latency reduction with better motor choice.

Abstract

The use of a cable-driven soft exosuit poses challenges with regards to the mechanical design of the actuation system, particularly when used for actuation along multiple degrees of freedom (DoF). The simplest general solution requires the use of two actuators to be capable of inducing movement along one DoF. However, this solution is not practical for the development of multi-joint exosuits. Reducing the number of actuators is a critical need in multi-DoF exosuits. We propose a switch-based mechanism to control an antagonist pair of cables such that it can actuate along any cable path geometry. The results showed that 298.24ms was needed for switching between cables. While this latency is relatively large, it can reduced in the future by a better choice of the motor used for actuation.